(2nd Edition at 20090424)
When you are chatting with your high school friend, it helps to be less professional and just occasionally goof a bit.
For example, a friend of mine was chatting on-line and he jokingly accused me (correctly) that I shouldn't romanized his Chinese name 波 (which literally means either "Ball" or "Wave" or "Radio Wave" in Chinese) as "Bo". In Hong Kong, people used to call him (in jyutping with tones) "bo1 zai2". To make it sound English like, it will be "b ao z ay" (if I used cmudict and my imagination). In Jyutping, 波 is indeed romanized as "Bo". Since I am familiarized with Jyutping, "Bo" became my first choice of romanization.
What my friend expect me to write is "Ball". The early sound translation of Ball happen to be, guess what, 波 . Some people will simply call him "Ball zai" on-line (or in mixed Jyutping-Enligh Bo1 l zai2). So most of the time, he preferred people call him "Ball zai".
When I considered his side of argument. I thought there is something's wrong. a large percentage of population in Hong Kong pronounce the word "Ball" without the "l" sound. (i.e. even closer to Cantonese 波) So I even feel my romanization is legitimate. My first thought is "how can "Ball" be a romanization? What we are looking for is "B ao"! "Bo" should be the answer."
Nevertheless, my argument has serious flaw. "Bo" in American English is usually pronounced as "B ow". E.g. President Obama's dog is called "Bo".
So this is total mistake! My friend's name will become "煲仔" in Cantonese (literally means hot pot) if such a Romanization scheme! That's pretty bad.
I start to spend some of my quality time to think about this problem (to my BBN colleagues: that's when I can't work on work stuffs anymore) of what is the best romanization.
In my mind, goal of of romanization should be
1, mimic a language/dialect with English phonemes
2, convert it back to a legitimate word form.
3, the romanized form has to sound correct in both the target and in English.
There are probably 100 of romanizations for the Chinese language. Even in Cantonese, there is about 5 (Yale, LauJyut, YyutPing are what I remembered.....) Many educated people in Hong Kong try to communicate a sound in romanization. They might say "Chinese Character X sounds like romanization R". Such translation could be very tough at times. 波 happens to be a very good example.
Let's try other romanizations, how about "baw"? (rhymes with "jaw") Here we got a sound which is closer to what Hong Kongers speak of the character 波。 Unfortunately, it still require articulating "w" at the end. This is not what exactly Hong Kongers will do.
How about "boo"? Nope, usually this word is pronounced as "b uw" in English so this is even farther from "baw".
I tried out more words in my mind. Then I give up shooting at the air, I looked up CMUdict which contains around 100k entries of English pronounciations, I found that there is only one such word in English which totally fit to 波. (Looking up Merriam Webster would probably give us a more definitive answer. CMUdict is more a speech recognition dictionary.) The word is "Baugh". It is an English surname. You can't find its meaning in Merriam-Webster. Although, it solve the problem but it lost the literally meaning of "Ball". I feel lost by Phonetics. But if this is the answer, may be I should start to call my friend "Baugh" if I insist romanization is the Excalibur.
After this analysis, I start to realize the difficulty of inventing a romanization scheme. I also realize what the collective wisdom of Hong Kong offer --- it doesn't attempt to do a romanization per se. What it does is a *literal translation*. That's why 波 was eventually "romanized" as "Ball". Even though in Hong Kong, "l" is not usually pronounced.
This probably not only happen between English and Cantonese. In other pair of languages, the situation could be exactly opposite, for example if Japanese wants to "Katakanarize" 波, then they could do ボ. But when they make a literally translation, it will become ボ-ル。 So that explains why Japanese friends will occasionally lengthen the term "Ball" in English.
To all my friend whose name is 波 in Hong Kong, let me say from now on I will also call you "Ball zai" on-line. But I will still keep calling you "Bo1 zai2" in Hong Kong. It's a tough compromise but well, I will live with it.